This invention relates to a low color or colorless polymaleate which is prepared by aqueous solution polymerization of maleic acid, an allylic sulfonate monomer, and a polyvalent transition metal ion. The polymaleates are useful as permanent press agents for textiles, and in laundry detergents to minimize calcium carbonate encrustation.
Polymaleates are commonly used as water treatment agents, dispersing agents, and chelating agents in applications where color of the polymer is not critical. Since polymaleates generally appear dark brown in color, such polymers are inappropriate for many detergent and textile applications where low color is desirable. This is especially true where the polymer is to be applied to a textile, for example, as a durable press resin where a high color polymer may cause undesired color formation on the textile.
There are many processes for preparing polymaleates and copolymers thereof, for example, such processes are disclosed in U.S. Pat. Nos. 5,135,677; 5,064,563; 4,519,920; 4,555,557; 4,668,735; 4,589,995; and 4,659,793 wherein the polymaleates are prepared in an organic solvent or water. Unfortunately, these processes yield polymaleates which appear dark in color as evidenced by Gardner color number of greater than 8.
U.S. Pat. No. 4,709,091 describes a process for preparing polymaleic acid which involves neutralizing maleic acid in an aqueous medium with an alkali metal hydroxide or ammonia, polymerizing the maleic acid in the presence of an initiator, and adding a further amount of the alkali metal hydroxide or ammonia. U.S. Pat. No. 4,709,091 suggests that sulfonate comonomers may be used along with the maleic acid. The polymalic acid polymers, however, appear dark in color as evidenced by Gardner color number of greater than 8.
U.S. Pat. No. 6,020,297 describes the present invention. A terminal disclaimer has been included with the present application in regard to this prior art.
It has now been discovered that a low color or colorless polymaleate, as determined by a Gardner color number of 8 or less, may be prepared by aqueous solution polymerization comprising:
(a) 70 to 99.9 weight percent of maleic acid;
(b) 0.1 to 30 weight percent of an allylic sulfonate monomer having the formula 
wherein R1 is selected from the group consisting of H, C1-C4 alkyl, C1-C6 alkoxy, C6-C10 aryl, ester, and COOH; R2 is Oxe2x80x94R3 wherein R3 is selected from the group consisting of C1-C4 alkyl, C1-C6 alkoxy, and C6-C10 aryl; n is from 0 to 1; and M+ is a cation selected from the group consisting of H+, NH4+, alkali metals, alkaline earth metals, and quaternary organic amines; and
(c) 0.5 to 50 xcexcm, based on the moles of monomer, of a polyvalent transition metal ion selected from group consisting of Group IVA, VA, VIA, VIIA, VIIIA, IB, IIB, and combinations thereof;
wherein the weight percents are based on the total weight of monomer, provided that 10 to 60 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.
According to an additional aspect the invention provides a method for imparting permanent press properties to a textile containing cellulose fibers wherein said method comprises (I) adding an aqueous solution of the low color or colorless polymaleate to a laundering process comprising at least one textile; and (II) heating the textile at a sufficient temperature for a sufficient time to react the polymaleate with the textile wherein water is removed from the textile, to impart permanent press properties to the textile. Optionally, the polymaleate is combined with a catalyst prior to Step (II).
According to an additional aspect the invention provides a low color or colorless polymaleate as determined by a Gardner color number of 8 or less, said polymaleate is prepared by aqueous solution polymerization comprising 70 to 100 weight percent, based on the total weight of monomer, of maleic acid; and 0.5 to 50 xcexcm, based on the moles of monomer, of a polyvalent transition metal ion selected from group consisting of Group IVA, VA, VIA, VIIA, VIIIA, IB, IIB, and combinations thereof; provided that 40 to 55 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.
The low color or colorless polymaleate of the present invention provides permanent press properties to textiles treated therewith and increases the resistance of such textiles to laundering abrasion. Such treated textiles display a significant reduction in wrinkles compared with nontreated textiles. Moreover, the treated textiles have a tactile sensation of feeling soft and retain their smoothness after laundering.
According to a further aspect the invention provides a cleaning composition containing a surfactant and the polymaleate. The polymaleate enhances or xe2x80x9cbuildsxe2x80x9d the cleaning efficiency of a surfactant by inactivating hardness ions such as calcium and magnesium, and other metal ions such as iron. The polymaleates soften water by sequestration. In addition, the polymaleates assist in cleaning by dispersing and suspending soils to prevent the redeposition of soils onto cleaned substrates. Fabrics washed with detergent compositions containing the polymaleate of the invention have much less calcium carbonate deposited on the fabric as compared to fabrics washed without the polymaleate. Moreover, fabrics washed with detergent compositions containing the polymaleate of the invention display significantly less graying as compared to fabrics washed with detergent compositions without the polymaleates of the invention.
The low color or colorless polymaleate as determined by a Gardner color number of 8 or less is prepared by aqueous solution polymerization of (a) 70 to 99.9 weight percent of maleic acid, (b) 0.1 to 30 weight percent of an allylic sulfonate monomer, and (c) 0.5 to 50 xcexcm, based on the moles of monomer, of a polyvalent transition metal ion selected from group consisting of Group IVA, VA, VIA, VIIA, VIIIA, IB, IIB, and combinations thereof. The weight percents of the maleic acid and allylic sulfonate monomer are based on the total weight of monomer used to prepare the polymaleate.
In another embodiment of the invention, a low color or colorless polymaleate as determined by a Gardner color number of 8 or less is prepared by aqueous solution polymerization of 70 to 100 weight percent, based on the total weight of monomer, of maleic acid; and 0.5 to 50 xcexcm, based on the moles of monomer, of a polyvalent transition metal ion selected from group consisting of Group IVA, VA, VIA, VIIA, VIIIA, IB, IIB, and combinations thereof, provided that 40 to 55 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.
As used herein, xe2x80x9cpolymaleatexe2x80x9d includes copolymers and terpolymers, etc., of maleic acid. Preferably, the amount of maleic acid which is used to prepare the polymaleate is greater than 80 weight percent, more preferably greater than 90 weight percent, based on the total weight of monomers. Most preferably, the amount of maleic acid monomer which is used to prepare the polymaleate is greater than 98 weight percent. Preferably, the amount of allylic sulfonate monomer which is used to prepare the polymaleate is less than 20 weight percent, more preferably 8 or less weight percent, based on the total weight of monomers. Most preferably, the amount of allylic sulfonate monomer which is used to prepare the polymaleate is less than 2 weight percent.
The maleic acid may be present as maleic acid and/or maleic anhydride. In the embodiment of the invention wherein an allylic sulfonate comonomer is used with the maleic acid, 10 to 60 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization. Preferably 20 to 50 mole percent, more preferably 30 to 40 mole percent, of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.
The allylic sulfonate monomer has the formula 
wherein R1 is selected from H, C1-C4 alkyl, C1-C6 alkoxy, C6-C10 aryl, ester, and COOH; R2 is Oxe2x80x94R3 wherein R3 is selected from C1-C4 alkyl, C1-C6 alkoxy, and C6-C10 aryl; n is from 0 to 1; and M+ is a cation selected from H+, NH4+, alkali metals, alkaline earth metals, and quaternary organic amines. Preferred alkali metals are sodium and potassium. Particularly preferred allylic sulfonate monomers are sodium methallyl sulfonate, sodium allyl sulfonate, and sodium 1-allyloxy-2-hydroxypropyl sulfonate.
In one embodiment of the invention, the allylic sulfonate monomer is sodium methallyl sulfonate having the formula 
In one embodiment of the invention, the allylic sulfonate monomer is a copolymerizable surfactant having the formula 
In the embodiment of the invention wherein a comonomer is not used with the maleic acid, 40 to 55 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization. Preferably 45 to 50 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.
The polyvalent transition metal ion is used to prepare the polymaleates of the invention in an amount of from 0.5 xcexcm to 50 xcexcm, based on total moles of monomer used to prepare the polymaleate. Suitable polyvalent transition metal ions are selected from Group IVA, VA, VIA, VIIA, VIIIA, IB, and Group IIB transition metal ions. Combinations of transition metal ions may also be used. Preferably the transition metal ion is selected from vanadium ions, iron ions, and copper ions. The polyvalent transition metal ion is preferably used in an amount of from 1.6 to 33.2 xcexcm, and more preferably 8.3 to 16.6 xcexcm. If the amount of polyvalent transition metal ion used is less than 0.5 xcexcm, the residual monomer level in the polymaleate is unacceptable. If the amount of polyvalent transition metal ion used is greater than 50 xcexcm, the color of the polymaleate is unacceptable as determined by a Gardner color number of greater than 8.
In one embodiment, the polymaleate is used to impart permanent press properties to a textile containing cellulose fibers. As used herein, xe2x80x9cpermanent pressxe2x80x9d shall be synonymous with wrinkle resistance, durable press, dimensional stability, shrinkage resistance, and wrinkle recovery. An aqueous solution of the polymaleate is applied to a textile, and the textile is heated in the presence of a catalyst at a sufficient temperature for a sufficient time to react the polymaleate with the textile wherein water is removed from the textile, to impart permanent press properties to the textile. The polymaleate may be applied in the form of an aqueous solution or sprayed.
Any method of applying the polymaleate to the textile is acceptable. Preferably, the textile is impregnated with an aqueous solution of the polymaleate. As used herein, xe2x80x9cimpregnatexe2x80x9d refers to the penetration of the solution into the fiber matrix of the textile, and to the distribution of the solution in a preferably substantially uniform manner into and through the interstices in the textile. The solution therefore preferably envelopes, surrounds, and/or impregnates individual fibers substantially through the thickness of the textile as opposed to only forming a surface coating on the textile.
In a preferred embodiment of the invention, the aqueous solution of the polymaleate is applied to the textile in a textile manufacturing process as part of the durable press finishing operation.
The textiles may be woven or non-woven fabrics and include 100% cellulosic fabrics, for example, cotton, rayon, and linen, as well as blends, for example, polyester/cotton or polyester/rayon. Such blends preferably contain at least 20% of cellulose. Both white and colored (printed, dyed, yarn-dyed, cross-dyed, etc.) fabrics can be effectively treated with the polymaleate of this invention. The textiles may comprise new or used clothing including previously worn clothing and/or laundered clothing. Preferably, the textiles contain free hydroxyl groups.
A catalyst may be used to speed up the reaction between the polymaleate and textile. The catalyst also increases the degree of crosslinking in the reaction of the carboxyl groups on the polymaleate and hydroxyl groups on the textile. While not wishing to be bound by any theory, the inventors believe that the catalyst decreases the zeta potential or the amount of negative charge on the textile surface and thus increases the amount of polymaleate which is deposited on the textile or fabric from the aqueous solution. Any substance that can accept an electron pair from a base can be used as a catalyst.
Preferably, the catalyst is a Lewis acid catalyst selected from dibutyltindilaurate, iron(III)chloride, scandium(III)trifluoromethanesulfonic acid, boron trifluoride, tin(IV)chloride, Al2(SO4)3xH2O, MgCl2.6H2O, AlK(SO4)2.10H2O, and Lewis acids having the formula NXp wherein N is a metal, X is a halogen atom or an inorganic radical, and p is an integer of from 1 to 4, such as BX3, AIX3, FeX3, GaX3, SbX3, SnX4, AsX5, ZnX2, and HgX2. More preferably, the Lewis acid catalyst is selected from Al2(SO4)3xH2O, MgCl2.6H2O, AlK(SO4)2.10H2O. A combination of catalysts can also be used in the method of the invention.
The treated textile is cured at the normal temperatures provided by either a drying unit used in a textile manufacturing process such as a steam heated drying cylinder, an oven, or an iron. Drying temperatures generally range from about 90xc2x0 C. to about 300xc2x0 C. Such temperatures permit water to be removed, thereby inducing crosslinking between the polymaleate and textile.
The residence time of the textile in the dryer unit, oven, or in contact with an iron ranges from about 1 second to about 200 seconds, depending on the temperature. The actual residence time for a particular textile sample depends on the temperature, pressure, type of fabric, and the type and amount of catalyst. Preferably, the time and temperature required to cure the polymaleate with the textile ranges from about 2 to about 60 seconds at a textile temperature ranging from about 100xc2x0 C. to about 250xc2x0 C. After the textile with the solution of the polymaleate applied thereto is dried/cured, subsequent coatings or additives may be applied.
In a preferred embodiment, a textile treated with the polymaleate is ironed both on the inside and outside surfaces to maximize the amount of crosslinking and thus permanent press properties of the textile.
Preferred means of applying the aqueous solution of the polymaleate on a textile manufacturing machine are by puddle press, size press, blade coater, speedsizer, spray applicator, curtain coater and water box. Preferred size press configurations include a flooded nip size press and a metering blade size press.
Preferred means of applying the aqueous solution of the polymaleate on off-machine coating equipment in a textile manufacturing process are by rod, gravure roll and air knife. The solution may also be sprayed directly onto the textile or onto rollers which transfer the solution to the textile. In an especially preferred embodiment of the invention, impregnation of the textile with the aqueous solution of the polymaleate occurs by means of a puddle size press.
Preferred means of applying the aqueous solution of the polymaleate in a laundering process are by adding the solution to the rinse water during the rinse cycle in the laundering process. In an especially preferred embodiment of the invention, impregnation of the textile with the aqueous solution of the polymaleate occurs during the final rinse cycle in a laundering process. In an additional especially preferred embodiment of the invention, impregnation of the textile with the aqueous solution of the polymaleate occurs in a washing machine which contains at least one textile, the polymaleate and optionally a catalyst, wherein the washing machine is not operating so that the textile remains in contact with the treatment solution for a period of time to facilitate the impregnation of the treatment solution into the textiles. The washing machine is turned on to the spin cycle, the textiles are removed, dried and ironed.
Another preferred means of applying the aqueous solution of the polymaleate to a textile such as clothing is spraying by means of a pump or aerosol a solution of the polymaleate onto the textile and then ironing the textile.
The concentration of the polymaleate in the aqueous solution is sufficient to provide from about 0.1 to about 10 weight percent of polymaleate in the textile based on the oven-dry weight of the textile. Preferably, the concentration of polymaleate in the aqueous solution is sufficient to provide from about 1 to about 5 weight percent, more preferably from about 2 to about 4 weight percent of polymaleate in the textile based on the oven-dry weight of the textile.
In another embodiment, the low color or colorless polymaleates are used in a cleaning composition. The concentration of polymaleate in the cleaning composition is from 0.1 to 50 weight percent, preferably 0.5 to 20, based on the total weight of the cleaning composition. Examples of cleaning compositions are laundry detergents, prespotters, dishwashing detergents, and hard surface cleaners. Examples of articles which may be cleaned using the cleaning compositions are fabrics, such as clothing, linens, carpets, or upholstery; hard surfaces such as countertops, windows, floors, dishes, glasses or tiles; or automobiles.
The cleaning composition may be a solid or liquid composition. If the cleaning composition is solid, the cleaning composition may be in any of the usual physical forms, such as for example, powders, beads, flakes, bars, tablets, noodles, pastes, and slurries. If the cleaning composition is liquid, the cleaning composition preferably disperses or solubilizes the polymaleate. The cleaning composition may be aqueous or nonaqueous. For example, the polymaleate may be dissolved or dispersed in water, in one or more solvents or inert diluents. Preferably the cleaning composition is aqueous.
The cleaning compositions may contain any additional components which are used in cleaning compositions. Such additional components are well known to those skilled in the art and include one or more surfactants, builders, ion exchangers, alkalies, anticorrosion materials, antiredeposition materials, optical brighteners, fragrances, dyes, chelating agents, enzymes, whiteners, brighteners, antistatic agents, sudsing control agents, solvents, hydrotropes, bleaching agents, perfumes, bleach precursors, water, buffering agents, soil removal agents, soil release agents, softening agents, opacifiers, inert diluents, buffering agents, corrosion inhibitors, graying inhibitors, anti-redeposition agents, stabilizers, opacifiers, fillers, builders, phosphate co-builder, and phosphate-replacer builder. Combinations of such additional components may also be used.
Preferably cleaning compositions prepared using the polymaleates contain at least one surfactant. Suitable surfactants include nonionic, anionic, cationic, and amphoteric surfactants. The surfactants usable in the cleaning composition may also be soaps.
Anionic surfactants include, for example, from C8 to C12 alkylbenzenesulfonates, from C12 to C16 alkanesulfonates, from C12 to C16 alkylsulfates, from C12 to C16 alkylsulfosuccinates or from C12 to C16 sulfated ethoxylated alkanols.
Nonionic surfactants include, for example, from C6 to C12 alkylphenol ethoxylates, from C12 to C20 alkanol alkoxylates, and block copolymers of ethylene oxide and propylene oxide. Optionally, the end groups of polyalkylene oxides can be blocked, whereby the free OH groups of the polyalkylene oxides can be etherified, esterified, acetalized and/or aminated. Another modification consists of reacting the free OH groups of the polyalkylene oxides with isocyanates. The nonionic surfactants also include C4 to C18 alkyl glucosides as well as the alkoxylated products obtainable therefrom by alkoxylation, particularly those obtainable by reaction of alkyl glucosides with ethylene oxide.
Cationic surfactants contain hydrophilic functional groups where the charge of the functional groups are positive when dissolved or dispersed in an aqueous solution. Typical cationic surfactants include, for example, amine compounds, oxygen containing amines, and quaternary amine salts.
Amphoteric surfactants contain both acidic and basic hydrophilic groups. Amphoteric surfactants are preferably derivatives of secondary and tertiary amines, derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. The cationic atom in the quaternary compound can be part of a heterocyclic ring. The amphoteric surfactant preferably contains at least one aliphatic group, containing about 3 to about 18 carbon atoms. At least one aliphatic group preferably contains an anionic water-solubilizing group such as a carboxy, sulfonate, or phosphono.
Generally, anionic surfactants, such as linear alkyl sulfonates (LAS) are preferred for use in solid cleaning compositions containing the polymaleate. Nonionic and anionic surfactant mixtures such as alcohol ethoxylates and LAS are preferred in liquid cleaning compositions containing the polymaleate. The surfactants are optionally present in an amount of from about 0 to about 50 weight percent, preferably from about 2 to about 45 weight percent, and more preferably from about 5 to about 40 weight percent of the cleaning composition.
Examples of builders which may be present in the cleaning composition include, for example, phosphates, such as pyrophophates, polyphosphates, or sodium tripolyphosphate. Further examples are zeolites, sodium carbonate, poly(carboxylic acids), nitriloacetic acid, citric acid, tartaric acid, the salts of the aforesaid acids and the monomeric, oligomeric, or polymeric phosphonates. Combinations of builders may also be used. The builders are optionally present in an amount of from 0 to about 85 weight percent, preferably from about 5 to about 50 weight percent based on the total weight of the cleaning composition.
Liquid cleaning compositions containing the polymaleate can contain up to 80 weight percent water or solvents or combinations thereof. Typical solvents which may be used include oxygen containing solvents such as alcohols, esters, glycol, and glycol ethers. Alcohols that may be used in the cleaning compositions include, for example, methanol, ethanol, isopropanol, and tertiary butanol. Esters which may be used include, for example, amyl acetate, butyl acetate, ethyl acetate, and esters of glycols. Glycols and glycol ethers that are useful as solvents include, for example, ethylene glycol, propylene glycol, and oligomers of ethylene or propylene glycol.
Solid cleaning compositions containing the polymaleate preferably contain up to 60 weight percent of one or more solid inert diluents such as sodium sulfate, sodium chloride, sodium borate, or selected polymers such as polyethylene glycol or propylene glycol.
In a cleaning composition, the polymaleate enhances or xe2x80x9cbuildsxe2x80x9d the cleaning efficiency of a surfactant by inactivating hardness ions such as calcium and magnesium, and other metal ions such as iron. The polymaleates soften water by sequestration. In addition, the polymaleates assist in cleaning by dispersing and suspending soils to prevent the redeposition of soils onto cleaned substrates.
The following nonlimiting examples illustrate further aspects of the invention.